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Code Issues Releases Activity

Fix for Due Wire library

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Fix reading and use of TWI status register.
Also, update endTransmission to be compatible with original & give more
useful return.
This commit is contained in:
Chris 2014-04-06 20:25:31 +01:00 committed by Cristian Maglie
parent 4d5d0f68bd
commit e079baa18d
1 changed files with 39 additions and 17 deletions
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50
hardware/arduino/sam/libraries/Wire/Wire.cpp
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@ -29,9 +29,13 @@ static inline bool TWI_FailedAcknowledge(Twi *pTwi) {
}
static inline bool TWI_WaitTransferComplete(Twi *_twi, uint32_t _timeout) {
while (!TWI_TransferComplete(_twi)) {
if (TWI_FailedAcknowledge(_twi))
uint32_t _status_reg = 0;
while ((_status_reg & TWI_SR_TXCOMP) != TWI_SR_TXCOMP) {
_status_reg = TWI_GetStatus(_twi);
if (_status_reg & TWI_SR_NACK)
return false;
if (--_timeout == 0)
return false;
}
@ -39,22 +43,32 @@ static inline bool TWI_WaitTransferComplete(Twi *_twi, uint32_t _timeout) {
}
static inline bool TWI_WaitByteSent(Twi *_twi, uint32_t _timeout) {
while (!TWI_ByteSent(_twi)) {
if (TWI_FailedAcknowledge(_twi))
uint32_t _status_reg = 0;
while ((_status_reg & TWI_SR_TXRDY) != TWI_SR_TXRDY) {
_status_reg = TWI_GetStatus(_twi);
if (_status_reg & TWI_SR_NACK)
return false;
if (--_timeout == 0)
return false;
}
return true;
}
static inline bool TWI_WaitByteReceived(Twi *_twi, uint32_t _timeout) {
while (!TWI_ByteReceived(_twi)) {
if (TWI_FailedAcknowledge(_twi))
uint32_t _status_reg = 0;
while ((_status_reg & TWI_SR_RXRDY) != TWI_SR_RXRDY) {
_status_reg = TWI_GetStatus(_twi);
if (_status_reg & TWI_SR_NACK)
return false;
if (--_timeout == 0)
return false;
}
return true;
}
@ -175,22 +189,30 @@ void TwoWire::beginTransmission(int address) {
// devices will behave oddly if they do not see a STOP.
//
uint8_t TwoWire::endTransmission(uint8_t sendStop) {
uint8_t error = 0;
// transmit buffer (blocking)
TWI_StartWrite(twi, txAddress, 0, 0, txBuffer[0]);
TWI_WaitByteSent(twi, XMIT_TIMEOUT);
int sent = 1;
if (!TWI_WaitByteSent(twi, XMIT_TIMEOUT))
error = 2; // error, got NACK on address transmit
if (error == 0) {
uint16_t sent = 1;
while (sent < txBufferLength) {
TWI_WriteByte(twi, txBuffer[sent++]);
TWI_WaitByteSent(twi, XMIT_TIMEOUT);
if (!TWI_WaitByteSent(twi, XMIT_TIMEOUT))
error = 3; // error, got NACK during data transmmit
}
}
TWI_Stop( twi);
TWI_WaitTransferComplete(twi, XMIT_TIMEOUT);
// empty buffer
txBufferLength = 0;
if (error == 0) {
TWI_Stop(twi);
if (!TWI_WaitTransferComplete(twi, XMIT_TIMEOUT))
error = 4; // error, finishing up
}
txBufferLength = 0; // empty buffer
status = MASTER_IDLE;
return sent;
return error;
}
// This provides backwards compatibility with the original